Recent research has indicated that people in a good mood tend to perform better on creativity or divergent thinking tasks and worse on tasks requiring systematic, analytic thinking than do people in other moods. Hypotheses regarding the processes underlying these effects can be grouped into those that propose that mood influences performance by affecting what is retrieved from memory and those that propose that mood influences performance because it affects the performer's motivation. The primary goal of the present project was to ascertain whether the effects were better accounted for by retrieval or motivational explanations. The tasks used in the experiments were the Remote Associates Test, on which performance was enhanced by a positive mood induction in previous research, and syllogisms, which are similar to tasks on which people in a positive mood have done relatively poorly in previous research.No significant relationship was obtained between mood condition (positive or neutral) and performance on Remote Associates Test items. Thus, explanations for previous findings that positive mood enhances performance on that and similar tasks could not be tested.Positive mood subjects performed significantly worse on the syllogisms than control subjects.Positive mood subjects were significantly more likely than control subjects to choose universal ("All A are C" or "No A are C") rather than particular ("Some A are C" or "Some A are not C") conclusions as their answers, were somewhat less likely to diagram the relationships among the premises, and were somewhat more likely to select an answer consistent with the atmosphere heuristic. Moreover, subjects spent considerably less time, on average, than was allotted for the syllogisms, with positive mood subjects spending somewhat less time than controls. Thus, in general, these results were more consistent with motivational accounts of the observed performance decrement than with retrieval accounts.